// // detail/posix_event.hpp // ~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2014 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #ifndef BOOST_ASIO_DETAIL_POSIX_EVENT_HPP #define BOOST_ASIO_DETAIL_POSIX_EVENT_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include <boost/asio/detail/config.hpp> #if defined(BOOST_ASIO_HAS_PTHREADS) #include <pthread.h> #include <boost/asio/detail/assert.hpp> #include <boost/asio/detail/noncopyable.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { namespace detail { class posix_event : private noncopyable { public: // Constructor. BOOST_ASIO_DECL posix_event(); // Destructor. ~posix_event() { ::pthread_cond_destroy(&cond_); } // Signal the event. (Retained for backward compatibility.) template <typename Lock> void signal(Lock& lock) { this->signal_all(lock); } // Signal all waiters. template <typename Lock> void signal_all(Lock& lock) { BOOST_ASIO_ASSERT(lock.locked()); (void)lock; state_ |= 1; ::pthread_cond_broadcast(&cond_); // Ignore EINVAL. } // Unlock the mutex and signal one waiter. template <typename Lock> void unlock_and_signal_one(Lock& lock) { BOOST_ASIO_ASSERT(lock.locked()); state_ |= 1; bool have_waiters = (state_ > 1); lock.unlock(); if (have_waiters) ::pthread_cond_signal(&cond_); // Ignore EINVAL. } // If there's a waiter, unlock the mutex and signal it. template <typename Lock> bool maybe_unlock_and_signal_one(Lock& lock) { BOOST_ASIO_ASSERT(lock.locked()); state_ |= 1; if (state_ > 1) { lock.unlock(); ::pthread_cond_signal(&cond_); // Ignore EINVAL. return true; } return false; } // Reset the event. template <typename Lock> void clear(Lock& lock) { BOOST_ASIO_ASSERT(lock.locked()); (void)lock; state_ &= ~std::size_t(1); } // Wait for the event to become signalled. template <typename Lock> void wait(Lock& lock) { BOOST_ASIO_ASSERT(lock.locked()); while ((state_ & 1) == 0) { state_ += 2; ::pthread_cond_wait(&cond_, &lock.mutex().mutex_); // Ignore EINVAL. state_ -= 2; } } private: ::pthread_cond_t cond_; std::size_t state_; }; } // namespace detail } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #if defined(BOOST_ASIO_HEADER_ONLY) # include <boost/asio/detail/impl/posix_event.ipp> #endif // defined(BOOST_ASIO_HEADER_ONLY) #endif // defined(BOOST_ASIO_HAS_PTHREADS) #endif // BOOST_ASIO_DETAIL_POSIX_EVENT_HPP